The Collaborative Stepped Care intervention is a complex intervention comprising the following components: screening for detection of cases; psycho-education; antidepressants; inter-personal therapy; yoga; specialist supervision & adherence management. The method of delivery will be based on the stepped-care model which provides treatments according to the patients' needs and incorporates strategies to overcome challenges to the integration of mental health in primary care in developing countries. This will be compared with Enhanced Usual Care which will comprise screening for detection of cases, provision of the diagnosis to the doctor, and making antidepressants available in the facility-all these components will be available in the Collaborative Stepped care facilities as well. The intervention will be delivered by two new, full-time, primary care human resources-the Health Assistant (in both arms) who will screen adult attenders; and in the Collaborative Stepped Care arms, the Health Counselor-who has been trained over 3 months, and a part-time Psychiatrist supporting the primary care team.